Bobbin-carrier.



R. K. HOHMANN.

BOBBIN CARRIER.

APPLICATION FILED MAY 19, 1910.

IIIHIJ Ill"! Patented N 0V. 28, 1911.

2 SHEETS-SHEET 1.

R. K. HOHMANN.

BOBBIN CARRIER.

APPLICATION FILED MAY 19, 1910.

1,009,749. Patented Nov. 28, 1911.

2 SHEETS-SHEET 2.

COLUMBIA PLANOORAPH $0., WASHINGTON, D c.

UNITED STATES PATENT OFFICE.

RICHARD K. I-IOHMANN, OF SAN DIEGO, CALIFORNIA.

BOBBIN- CARRIER.

rename.

T 0 all whom 2'25 may concern Be it known that I, RICHARD K. Hort- MANN, a citizen of the United States, and resident of San Diego, in the county of San Diego and State of California, have invented certain new and useful Improvements in Bobbin-Carriers, of which the following is a specification.

This invention relates to bobbin carriers for rotary sewing machines, and particularly to such bobbin carriers as are adapted to contain either an ordinary spool of thread or a bobbin.

It is an improvement upon the construction disclosed in my Patent No. 983,902, February 14, 1911. Its objects are to re duce the size of the bobbin carrier while permitting it to receive an ordinary'spool, to make it easy to insert and remove the spool, to facilitate the passage of the loop of thread around the bobbin carrier, and generally to improve the structure and operation.

To these ends the invent-ion consists in the novel features of construction which will be apparent from the following description taken in connection with the accompanying drawings.

In the drawings: Figure 1 is a front elevation of a portion of a sewing machine having my invention applied thereto. Fig 2 is a front view of my bobbin carrier in open condition with a spool therein. Fig. 3 is a side view of the bobbin carrier when closed surrounded by the looper. Fig. 1 is a side view of the spool holder having a spool therein. Fig. 5 is a plan view of what is shown in Fig. 4; Fig. 6 is a perspective view of the spool holder with the spool removed; Fig. 7 is a perspective view of the arm used to prevent rotation of the bobbin carrier and Fig. 8 is a perspective view of the hinged door portion of the bobbin car-' rier.

In these drawings, 1 represents the work table and 2 the head of a sewing machine.

The machine is provided with any ordinary needle bar 3, take-up 1 and presser foot 5, and these constitute no part of my present invention.

My invention relates entirely to the construction of'the bobbin carrier carrying the lower spool of thread, and the means for carrying the loop of thread around the bobbin carrier. 7

As is shown clearly in Fig. 2, my bobbin Specification of Letters Patent.

Application fi1ed May 19, 1910.

Patented Nov. 28, 1911.

Serial No. 562,257.

carrier embodies an outer marginal ringlike bearing 6 which is cut away throughout part of its circumference, and is provided with a loop engaging hook 20 at the edge of and facing said cutaway portion. Thin bulging side walls of metal 7 and 8 constitute the casing which contains the spool or bobbin and they are joined at their edges to the ring 6. These walls extend outwardly from the ring at sul'licient angle to permit the loop of thread to pass easily over the casing andethey are cut away at one edge to correspond with the cutaway portion of the bearing rim. In the present form of my invention the spool is placed in the bobbin carrier with its axis in the plane of the bearing rim, and this permits making the shuttle much smaller than would be the case if the spool were placed at right angles to the plane of the rim.

In order to permit easy access to the interior of the bobbin carrier for the purpose of inserting and removing the spool, and also to provide convenient and ei'licient means for properly holding the spool in place, I make use of a hinged door 9 in the wall 8 of the casing. is of a length slightly greater than an ordinary spool of thread, and the spool is adapted to be supported on and swing with this door when it is opened. This door is semi-cylindrical in form and is hinged at 10 on the opposite side of the casing from the cutaway portion, and when in normal position, as shown in Fig. 1, the hinge extends at an angle of about sixty degrees to the horizontal. The central plate-like extension 11 at one end of the door is bent at right angles thereto and extends within the casing. This plate carries a post 12 parallel with the walls of the door and at its axis whereby it occupies a position centrally of the shuttle when the door is closed. A spool holder shown in Fig. (3 is adapted to be mounted on. the spindle or post 12 whereby that holder will be carried by the door.

The holder embodies a circular disk 13 at one end having a central tubular shaft 14- which is adapted to fit over the post 12. A semi-cylindrical flange 15 extends from the edge of disk 13 throughout part of its circumference and is provided with the angular extension 16 at one edge of its free end. The free edge of the door 9 is provided at its lower end with an angular hook-shaped portion 17 which is adapted to receive and interlock with the extension 16 of the spool holder. \Vhen the tubular shaft 14 is placed on the post 12 and the holder is in position the straight edge 18 of the flange 15 is against the free edge of the door 9 and the flange constitutes a continuation of that door. The opposite edge 19 of the flange is rounded and it extends from the door substantially covering the cutaway portions of the walls '7 and 8, and constituting a closure for that portion of the spool holder.

A metal piece 21 is secured to the rim 6 within its end opposite the hook 20 and it has an arm 22 extending parallel to the axis of the spool toward said hook across the cutaway portion as shown in Fig. 2. This arm is just outside of the flange 15 when the spool holder is in place and the door is closed, as shown in Fig. 1. The inner end of the piece 21 is preferably provided with a curved spring nfetal end 23 which is adapted to engage the plate-like extension 11 of the spool holder and act as a yielding latch to hold the door and spool in position when the door is closed. It will be understood however that my invention is not limited to this way of forming the latch.

As in my said patent my bobbin carrier isvadapted to be held against rotation in a rotary bearing which is provided with a hook for carrying the loop of thread around the bobbin carrier. The bearing ring 24 is shown in Fig. 3 and it is provided with a hook 25 which engages the loop of thread to carry it around the bobbin carrier. The bearing surface of the ring 24 is cut away justin advance of the hook 25, as shown in Fig. 3, so as to permit the free passage of the loop of thread. This revolving hook mechanism is carried by a rotary shaft 26 which in the operation of the machine turns continuously in a single direction. It has the flaring arms 27 carrying the ring 28 at their outer ends and this ring fits in the ring 24. The two rings are secured together by the bayonet joint consisting of the slots 29 and pins 30. The revolving hook thus turns continuously with the shaft 26 around the bobbin carrier.

In order to prevent the bobbin carrier from turning with the revolving holder, 1 make use of an arm 31 secured to some fixed part of the machine such as the under surface of the table and having a portion extending within the cutaway portion of the bobbin carrier, so as to stand in its way. It stands in such position as to make contact with the rounded end of the spring 32 mounted on the outside of arm 22. At the point of contact I preferably place a roller 33 for the purpose of reducing friction, since the loop of thread must be drawn over the arm 22 and hence under the roller 33. I find that the spring 32 and roller 33 re duce the friction on the thread to a minimum. The arm 31 is provided with two fingers 34 and 35 curved in planes at substantially right angles to each other from the point where the arm makes contact with the bobbin carrier. The finger 34 extends down. around the periphery of the revolving hook to guide the thread and the finger 35 extends down centrally over the face of the bobbin carrier for a similar purpose. They prevent the loop of thread from twisting and becoming caught in the mechanism.

In order to give the thread drawn from the bobbin carrier the proper tension without the necessity for adjustable tension springs I make use of the construction shown particularly in Figs. 4 and 5. The spool 36 or the bobbin is carried by the shaft 14 and is rotatable thereon and the thread from it is first drawn through the slot 37, then around the two tension hooks 38, 39 placed at the edge of flange 15, then under the end 40 of the irregular fixed plate 41, secured to the outer face of the disk 13, then up through the slot or notch 42 in the fixed plate and then down through the narrow elongated slot 43. From this point the thread goes up to the point where it is interlocked with the upper thread to form the stitch. It will be thus apparent that my thread holder is bodily removable from the bobbin carrier and contains the necessary tension mechanism so that all of the threading operation can be conveniently done and the holder may then be easily and quickly slipped into place. I furthermore find that the tension mechanism described operates automatically and places the requisite tension on threads of various sizes without any necessity for adjustment.

It will be understood that when the spool or bobbin is placed on the shaft- 14 of the spool holder and the threading operation is completed, the holder is slipped into place on the post 12 of the door 9 and that door is closed and is held closed by the spring latch 23.

It is believed that the operation of the device will be understood by those skilled in the art from the above description of the mechanism. The loop of thread formed by l the descent of the needle will be in the path of the hook 25 and will be engaged thereby so that the rotation of that hook will carry the loop forward spreading it so that it will travel up the inclined sides of the bobbin carrier which is held against rotation and will thus pass entirely around the bobbin carrier. The lower thread will thus pass through the loop of the upper thread and be locked.

lVithout limiting myself to the particular construction shown, what I claim is:

1. In a device of the class described, the combination with a bobbin carrier, of a removable spool holder embodying an end disk, a central spindle for said spool and a surrounding flange provided with a slot and tension hooks for the thread, and a fixed plate on said disk provided with notches and adapted to permit the thread to pass beneath it and through the notches.

2. A bobbin carrier for a rotary sewing machine embodying a casing having a circular bearing rim and inclined sides one of said sides being provided with a door in combination with a spindle carried by said door, and a removable spool holder adapted to be placed 011 said spindle.

3. A bobbin carrier for a rotary sewing machine embodying a casing having a circular bearing rim and inclined sides one of said sides being provided with a door in combination with a spindle carried by and parallel with said door, and a removable spool holder adapted to be placed on said spindle.

4. A bobbin carrier for a rotary sewing machine embodying a casing having a circular bearing rim and inclined sides one of said sides being provided with a door in combination with a spindle carried by and parallel with said door, adapted to carry a spool.

5. In combination with a bobbin carrier casing provided with a hinged door, of a removable spool holder, means on said door for supporting said holder, and a flange on said holder partially surrounding the spool and constituting a continuation of the wall of said door.

6. In combination with a bobbin carrier casing provided with a hinged door, of a removable spool holder, means on said door for supporting said holder, and a flange on said holder partially surrounding the spool and constituting a continuation of the wall of said door, and means for interlocking said flange with said door.

7. A bobbin carrier for a rotary sewing machine embodying a casing having a circular bearing rim and inclined sides, the said rim and sides being cut away throughout part of the circumference, a hinged door in one of said sides, a removable spool holder adapted to be carried by said door, and a semi-cylindrical flange on said holder adapt ed to extend across the cutaway portion of the casing from said door when the door is closed.

8. A bobbin carrier for a rotary sewing machine embodying a casing having a circular bearing rim and inclined sides, the said rim and sides being cut away throughout part of the circumference, a hinged door in one of said sides, a removable spool holder adapted to be carried by said door, a semicylindrical flange on said holder adapted to extend across the cutaway portion of the casing from said door when the door is closed, and a bearing arm extending from said bearing rim over said flange to serve as a stop.

9. A bobbin carrier for a rotary sewing machine embodying a casing having a circular bearing rim and inclined sides, the said rim and sides being cut away throughout part of the circumference, a hinged door in one of said sides, a removable spool holder adapted to be carried by said door, a semicylindrical flange on said holder adapted to extend across the cutaway portion of the casing from said door when the door is closed, a bearing arm extending from said bearing rim over said flange to serve as a stop, and a rounded spring surface on said arm in combination with a fixed arm carry ing a roller making engagement with said spring surface.

10. The combination with a bobbin carrier for rotary sewing machines having a part of its circumference cut away, of a 1'0- tary hook engaging said bobbin carrier at its periphery and adapted to carry a loop of thread around it, a fixed arm extending into said cutaway portion and provided with a roller, and rounded spring on said bobbin carrier engaged by said roller.

11. The combination with a bobbin carrier tor rotary sewing machines having a part of its circumference cut away, of a rotary hook engaging said bobbin carrier at its periphery and adapted to carry a loop of thread around it, a fixed arm extending into said cutaway portion and provided with a roller, a rounded spring on said bobbin carrier engaged by said roller, and curved fingers extending from said arm around the bobbin carrier to prevent twisting of the loop of thread.

In testimony whereof I a'lfix my signature in presence of two witnesses.

RICHARD K. HOHMANN.

\Vitnesses WM. I-IUMPHREY, HENRY BRAUN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

